Screw cap



Aug- 12, 1958 i B. G. cHRlsTlANssoN ETAL 2,847,139

Filed Aug. 11, 1955 Allg- 12, 1958 B. G. cHRlssANsrsoN ETAL 2,847,139

SCREW CAP Filed Aug. 11, 1955 v 2 Sheets-Sheet 2 NVENTOR, l5. G; Clzristuhstson p and BYi T ZOIIZ berg, W i@ 91 ELM@ SCREW CAP rBro; GnnhnvarV Christiansson, StockholmvVallingby, and

The present invention relates to a screw cap for bottles, containers-andthe like, which are particularly intended for the storage of substances injurious to children.

`The purpose of the invention is to make a` screw cap,

which cannot =be opened by children, and this is achieved according to the invention by making it necessary to subject the operating means of the cap to a composite movement which is complicated to small children and which requires an essential strength at least in certain cases. For this purpose the essential features of the in vention are that the cap has a casing or the like rotatably arranged outside the cap, said casing being normally kept out of engagement with the cap at least by one spring but being lconveyable in engagement with the cap against the action of the spring, whereby projections or recesses of the casing engage with corresponding recesses or projections of the cap, so that the cap 4can `be screwed olf only when the casing is subjected to both pressure, traction and torsion.

Further objects and advantages will become apparent from the following detailed description, reference being had to the accompanying drawings showing three embodiments, chosen by way of example, of the screw cap according to the present invention.

Fig. l is a longitudinal section of the screw cap according to one embodiment arranged at a bottle or the like,

Fig. 2 is a longitudinal section of the cap according to the second embodiment,

Figs. 3 to 6 show the cap according to the third embodiment, Fig. 3 being substantially a longitudinal section of all parts included in the cap in a disassembled state,"

Fig. 4 is a top View of the spring pertaining to the cap,

Fig. 5 is a top view of the cap, and

Fig. 6 shows the parts according to Fig. 3 of the cap in the'assembled state of the cap.

A screw cap 1 is provided with a centrally mounted pivot 2. On the pivot 2 a casing 3 or the like is rotatably mounted, which encloses the screw cap 1. Between the cap 1 and the casing 3 a spring 4 is mounted which strives to let the casing 3 rest `against a stop 5 arranged at the free end 'of the pivot 2. According to the embodiment-shown in Figs. 1 and 2 the spring 4 consists of a screw cap arranged around the pivot 2.

According to the embodiment shown in Fig. l, the casing 3 at its portion facing the top side ofthe `cap 1 is provided with a pair of pivots 6, whilst the cap at its top side 'is provided with a great many holes or similar recesses 7 corresponding to the cross section of the pivots 6. The pivots 6 are adapted to engage with the holes 7, when the casing 3 is pressed against the cap 1 against the action of the spring 4, so that the cap 1 can be turned for its opening and closing when the casing is subjected to pressure and torsion. The pressure is dependent on the properties of the spring 4, for which reason it can without difficulty be given the size desired.

The threads of the cap 1 are given such a size and such a pitch that the frictional resistance between the N United States Patent() F 2,847,139 Patented Aug. l121958 threads of the cap and those oi the bottle is greaterthan I between the cap 1 and the'casing 3, when they means 6 and 7` do4 not engage with each other, whereby it is ensured that the cap 1 cannot be screwed oli the bottle, unless the caging atits turning is subjected to the. pressure determined bythe Spring 4- Y It is clear that the engagement means between the cap 1 and the casing 3 can be given another development than the one shown inFig. 1. The pivots 6 can thus for instance be .arranged at the cap 1 and the holes 7 in the casing 3, Accordingrto the embodiment shown in Fig. 2, the engagement means consist of shoulders 8 and 9. The shoulders 8 are mounted at. the periphery of the cap 1, whilst the shoulders 94 aremounted at the inner peripheral surface of the casing 3, the shoulders 9 being normally situated at some distance .as seen vertically from the shoulders 8, soV that the different shoulders 8 and 9 will only engage with each other,V at the torsion of the casing 3, when the casing 3 is subjected 'to pressure. The shoulders 8 and9may be replaced by tooth'rows, the teeth of which are then to engage with each-other, when the casing 3 is subjected to pressure.

According to :a further embodiment of the invention, the spring 4 may be disposed in such a way that in order to bring about the engagement between the cap 1 and the casing 3 it must be actuated by traction from the casing 3. The shoulders 9 at the casing are then, of course, to be disposed lower than the shoulders 8 of the cap 1.

According to this embodiment, the first thread or one of the rst threads of the cap 1 should be dimensioned in such a way that the frictional resistance between these and the threads of the bottle is less than between the cap 1 and the casing 3, so that the casing 3 need not be subjected to a pull when the cap 1 is screwed on the bottle.

It is clear from Fig. 2 that the stop 5 of the pivot 2 may be built into the casing 3, so that it has a smooth `and unbroken surface.

According to the embodiment shown in Figs. 3-6, the screw cap is provided with a stop device, which at the turning of the casing 3 for screwing on the cap 1 is mounted to unite the casing 3 with the cap 1, so that the .cap 1 and the casing 3 during the screwing operation move like .a unit. Hereby it is as easy to screw on the cap according to the invention as to screw on a cap consisting of a single part.

Like the embodiment shown in Fig. l, the casing 3 of the embodiment shown in Figs. 3-6 is provided with a pair of pivots 6 arranged at the portion of the casing 3 which faces the top side of the cap 1, whilst the cap at its top side is provided with a great many grooves or similar recesses 7 radially directed and corresponding to the cross section of the pivots 6. The pivots are adapted to engage with the grooves 7, when the casing 3 is pressed against the cap 1 against the action of the spring 4, so that the cap 1 can be turned for its opening only when the casing 3 is subjected to pressure and torsion.

The stop device which is adapted at the torsion of the casing 3 for screwing on the cap 1 to unite the casing 3 with the cap 1 is the spring 4, which has been given the shape of a circular plate of spring steel or the like, the peripheral portion of which has been shaped to four leaf springs 10 uniformly ydistributed and departing from the plane of the plate, the ends of which are situated in the radial plane. The circular plate is provided with a pair of holes 11 through which the projections or the pivots 6 pass, so that the spring is lixed at the casing 3. The ends of the plate springs' 10 are arranged to engage with the four grooves 7 of the top side of the cap 1 arranged at right angles to each other, the leaf springs 10 being directed so that their ends strike against the sides of the grooves when the casing 3 is turned in the direction for screwing it on. When the casing 3 on the contrary is turned in the direction for screwing it oi the ends of the plate springs 10 will snap over the grooves 7, for which reason the casing 3 is freely rotatable in that direction on the cap 1.

vThe stop device, however, may be embodied in a number of other ways. Thus, it may consist of a single leaf spring, which is disposed either between the top portion of the cap 1 and the casing 3 or between the peripheral portions of the cap 1 and the casing 3 which face each other. The stop device may also consist of a screw spring arranged around the pivot 2, one end of which is for instance anchored to the casing 3 and the second end of which is shaped so as to engage with a groove or the like in the cap 1 when the casing 3 is turned in the direction for screwing it on, but to snap over the groove when the casing 3 is turned in the direction for screwing it off.

The cap 1 is provided on the inside with a central pivot 12, to which there is anchored a sealing member 13 of plastic or the like and which is preferably conic.

A casing 14 closed at one end is mounted at the top of the casing 3 after drawing the screw of the pivot 2 tight.

The invention is not restricted to the features described above and shown in the drawings but may be varied in many ways within the scope of the appendant claim.

What we claim and desire to secure by Letters Patent A safety cap for a container comprising a cap having sealing means with said container, a casing rotatably mounted on said cap, plate means located between said cap and casing operative for uniting said cap and casing for sealing said cap to said container, said casing having spaced projections and said plate means having apertures through which said projections project in order to unite said plate means to said casing and said cap having recesses for cooperation with said projections in order to release said cap from said sealing means.

References Cited in the tile of this patent UNITED STATES PATENTS Sentman Nov. 17, 1936 Hale June 14, 1955 Bell Nov. 1, 1955 

